Organosilica-Modified Multiblock Copolymers for Membrane Gas Separation

Organosubstituted silica derivatives were synthesized and investigated as modifiers of block copolymers based on macroinitiator and 2,4-toluene diisocyanate. A peculiarity of the modified block copolymers is the existence in their structure of coplanar rigid polyisocyanate blocks of acetal nature (O-polyisocyanates). Organosubstituted silica derivatives have a non-additive effect on high-temperature relaxation and α-transitions of modified polymers and exhibit the ability to influence the supramolecular structure of block copolymers. The use of the developed modifiers leads to a change in the gas transport properties of block copolymers. The increase of the permeability coefficients is due to the increase of the diffusion coefficients. At the same time, the gas solubility coefficients do not change. An increase in the ideal selectivity for a number of gas pairs is observed. An increase in the selectivity for the CO2/N2 gas pair (from 25 to 39) by 1.5 times demonstrates the promising use of this material for flue gases separation.

Download Full-text

Synthesis and Study of Gas Transport Properties of Polymers Based on Macroinitiators and 2,4-Toluene Diisocyanate

Membranes ◽

10.3390/membranes9030042 ◽

2019 ◽

Vol 9 (3) ◽

pp. 42 ◽

Cited By ~ 2

Author(s):

Ilsiya M. Davletbaeva ◽

Ilnaz I. Zaripov ◽

Alexander I. Mazilnikov ◽

Ruslan S. Davletbaev ◽

Raphael R. Sharifullin ◽

...

Keyword(s):

Block Copolymers ◽

Gas Separation ◽

Gas Transport ◽

Toluene Diisocyanate ◽

Great Promise ◽

Internal Cavity ◽

Polar Molecules ◽

Supramolecular Organization ◽

Membrane Gas Separation ◽

Separation Membranes

Nowadays, block copolymers hold great promise for the design of novel membranes to be applied for the membrane gas separation. In this regard, microporous block copolymers based on a macroinitiator with an anionic nature, such as potassium-substituted block copolymers of propylene oxide and ethylene oxide (PPEG) and 2,4-toluene diisocyanate (TDI), were obtained and investigated as effective gas separation membranes. The key element of the macromolecular structure that determines the supramolecular organization of the studied polymers is the coplanar blocks of polyisocyanates with an acetal nature (O-polyisocyanate). In the present research, the influence of the content of peripheral polyoxyethylene (POE) blocks in PPEG on the supramolecular structure processes and gas transport characteristics of the obtained polymers based on PPEG and TDI was investigated. According to the study of polymers if the POE block content is 15 wt %, the polyoxypropylene segments are located in the internal cavity of voids formed by O-polyisocyanate blocks. When the POE block content is 30 wt %, the flexible chain component forms its own microphase outside the segregation zone of the rigid O-polyisocyanate blocks. The permeability for polar molecules, such as ammonia or hydrogen sulfide, significantly exceeds the permeability values obtained for non-polar molecules He, N2 and СН4. A relatively high permeability is also observed for carbon dioxide. At the same time, the content of POE blocks has a small effect on the permeability for all studied gases. The diffusion coefficient increases with an increase in the POE block content in PPEG for all studied gases.

Download Full-text

Tuning the morphology of segmented block copolymers with Zr-MOF nanoparticles for durable and efficient hydrocarbon separation membranes

Journal of Materials Chemistry A ◽

10.1039/d0ta02587a ◽

2020 ◽

Vol 8 (18) ◽

pp. 9382-9391 ◽

Cited By ~ 1

Author(s):

Ali Pournaghshband Isfahani ◽

Morteza Sadeghi ◽

Somaye Nilouyal ◽

Guoji Huang ◽

Ansori Muchtar ◽

...

Keyword(s):

Block Copolymers ◽

Gas Solubility ◽

Polymer Morphology ◽

Separation Membranes

PU/UiO66-NH2 membranes demonstrate exceptional C4H10/CH4 selectivity due to the enhanced gas solubility associated with MOFs and tuning the polymer morphology.

Download Full-text

Synthesis and Formation of Gas Separation Membranes Based on Polyalkylenesiloxanes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.816.233 ◽

2019 ◽

Vol 816 ◽

pp. 233-237

Author(s):

Ilya L. Borisov ◽

N.V. Ushakov ◽

E.A. Grushevenko ◽

E.S. Finkel’stein ◽

V.V. Volkov

Keyword(s):

Gas Separation ◽

Separation Process ◽

Membrane Gas Separation ◽

Gas Separation Membrane ◽

Separation Membranes ◽

Gas Separation Membranes ◽

Gas Transport Properties ◽

Separation Membrane ◽

Transport Component ◽

The Ideal

The membrane gas separation is currently a competitive separation process. The heart of the membrane gas separation process is the membrane, more precisely the material from which it is made. The search for a selective material to develop a gas separation membrane is an important task presently. Membrane materials with advantageous impact of sorption transport component is a good material for the selective fractionating С1-С4 hydrocarbons with obtaining methane fraction and C3+ fraction. Such materials are polyalkylenesiloxanes. In this work, the optimal concentration of a curing agent (tetraethoxysilane) was defined (5%). Such concentration is necessary for obtaining constant membrane film with high gas transport properties: the permeability coefficient for n-butane is 7400; the ideal selectivity of n-butane/methane is 25.5.

Download Full-text

Diffusion of Selective Penetrants in Interfacially Modified Block Copolymers from Molecular Dynamics Simulations

ACS Macro Letters ◽

10.1021/acsmacrolett.7b00023 ◽

2017 ◽

Vol 6 (4) ◽

pp. 375-380 ◽

Cited By ~ 10

Author(s):

Youngmi Seo ◽

Jonathan R. Brown ◽

Lisa M. Hall

Keyword(s):

Molecular Dynamics ◽

Block Copolymers ◽

Molecular Dynamics Simulations ◽

Modified Block ◽

Dynamics Simulations

Download Full-text

A new approach to multiblock copolymers using atom transfer radical coupling

e-Polymers ◽

10.1515/epoly.2005.5.1.510 ◽

2005 ◽

Vol 5 (1) ◽

Cited By ~ 2

Author(s):

René Nagelsdiek ◽

Helmut Keul ◽

Hartwig Höcker

Keyword(s):

Block Copolymers ◽

Bisphenol A ◽

Coupling Efficiency ◽

Chain Extension ◽

Multiblock Copolymers ◽

Atom Transfer ◽

Radical Species ◽

New Approach ◽

Radical Coupling ◽

Phenylene Oxide

AbstractAtom transfer radical coupling (ATRC) is a method for chain extension of styrene homopolymers prepared by atom transfer radical polymerization (ATRP). This concept is used to produce multiblock copolymers from block copolymers prepared via ATRP of styrene using various macroinitiators. ATRC comprises the reactivation of the dormant species at the chain ends. In the absence of monomer, the active radical species recombine to give chain extension (from polystyrene, PS) or multiblock copolymers (from block copolymers). The application of ATRC to PSblock- poly(bisphenol A carbonate)-block-PS (PS-b-PC-b-PS) was not successful because chain degradation of the PC block occurs. However, poly(phenylene oxide)-block-PS (PPO-b-PS) and PS-b-PPO-b-PS were successfully transformed into tri- and multiblock copolymers by ATRC, although the coupling efficiency is not as high as observed for PS oligomers under similar conditions.

Download Full-text

Segmented block copolymers of natural rubber and propylene glycol-toluene diisocyanate oligomers

Polymer Engineering & Science ◽

10.1002/pen.10205 ◽

1998 ◽

Vol 38 (3) ◽

pp. 440-451 ◽

Cited By ~ 20

Author(s):

C. J. Paul ◽

M. R. Gopinathan Nair ◽

N. R. Neelakantan ◽

Peter Koshy

Keyword(s):

Block Copolymers ◽

Natural Rubber ◽

Propylene Glycol ◽

Toluene Diisocyanate

Download Full-text

Effects of helium and other inert gases on Echinosphaerium nucleofilium (protozoa, heliozoa)

Journal of Experimental Biology ◽

10.1242/jeb.63.2.467 ◽

1975 ◽

Vol 63 (2) ◽

pp. 467-481

Author(s):

J. B. Miller ◽

J. S. Aidley ◽

J. A. Kitching

Keyword(s):

Hydrostatic Pressure ◽

Total Pressure ◽

Cell Damage ◽

Inert Gases ◽

Gas Solubility ◽

Reversal Effect ◽

Pressure Reversal ◽

Partial Pressures ◽

Solubility Coefficients ◽

Sites Of Action

The effects of helium, nitrogen, argon and krypton on Echinosphaerium nucleofilum (Heliozoa) have been studied at partial pressures of 10–130 atm. Additional experiments have been carried out with hydrostatic pressure alone. Helium causes shortening of the axopods over the whole range of pressures, and damage to the cell body at pressures of 60–90 atm, both with a maximum at 80 atm. These effects cannot be explained in terms of hydrostatic pressure alone; a ‘pressure reversal’ effect may be operating, causing the peak at 80 atm. Nitrogen also causes both cell damage and axopod shortening, the severity increasing with increasing pressure. Argon and krypton cause cell damage but no shortening. The order of potency for cell damage is krypton greater than argon greater than nitrogen greater than helium. It is suggested that there may be tuo sites of action, possibly the microtubules (for axopod shortening) and the cell membrane (for cell damage). In appropriate mixtures of helium and argon, both the cell damage usually caused by argon, and the axopod shortening usually caused by helium, are prevented. Possible mechanisms include the effects of hydrostatic pressure on gas solubility coefficients, reversal of the effects of the gases by the increase in total pressure, and competition for sites of action.

Download Full-text